Bradykinin B2 receptors in nodose ganglia of rat and human

The present study has employed in vitro electrophysiology to characterise the ability of bradykinin to depolarise the rat isolated nodose ganglion preparation, containing the perikarya of vagal afferent neurons. Both bradykinin and kallidin elicited a concentration-dependent (1-100 nM) depolarisation when applied to the superfusate bathing the nodose ganglia, whereas the bradykinin B-1, receptor agonist, des-Arg(9)-bradykinin, was only effective in the micromolar range. Furthermore, the electrophysiological response to bradykinin was antagonised by the bradykinin B, receptor antagonist, D-arginyl-L-arginyl-L-prolyl-trans-4-hydroxy-L-prolylglycyl-3-(2-thienyl)-L-alanyl-L-seryl-D-1,2,3,4-tetrahydro-3-isoquinolinecarbonyl-L-(2 alpha,3 beta,7 alpha beta)-octahydro-1H-indole-2-carbonyl-L-arginine (Hoe 140), in a concentration-related manner. To determine the anatomical location of functional bradykinin B, receptors, in vitro autoradiography with [I-125]para-iodophenyl Hoe 140 was performed on sections of rat and human inferior vagal (nodose) ganglia and confirmed the presence of binding over vagal perikarya. Collectively, these data provide evidence for functionally relevant bradykinin B, receptors on vagal afferent neurons, which are apparently also present on human vagal perikarya. (C) 1998 Elsevier Science B.V. All rights reserved.